The present invention relates to a capacitance type sensor, which specifically can be used as a joy stick or a pointing device.
The capacitance type sensor shown in FIG. 7 is developed by the inventors of the present application and a patent has been filed in Japan.
In FIG. 7, the capacitance type sensor includes a substrate 90, a movable electrode plate D, an operation part 92 and a fixing member 93. The substrate 90 has fixed electrodes Dx+, Dx−, Dy+, Dy− and Dz+ thereon. The movable electrode plate D has faces, and at least one of the faces which is opposing the fixed electrodes Dx+, Dx−, Dy+, Dy− and Dz+ is made of conductive rubber. The operation part 92 is made of silicone rubber and integrally formed with the movable electrode plate D. The fixing member 93 presses down the movable electrode plate D and the operation part 92 and prevents them from separating from the substrate 90.
The fixed electrodes Dx+, Dx−, Dy+, Dy− and Dz+ and the movable electrode plate D form a plurality of variable capacitance parts Cx+, Cx−, Cy+, Cy− and Cz+, and the capacitance of each of the variable capacitance parts Cx+, Cx−, Cy+, Cy− and Cz+ changes in accordance with the magnitude and the direction of the force applied to the operation part 92.
In the above capacitance type sensor, in order to ensure a gap between the movable electrode plate D and the fixed electrodes Dx+, Dx−, Dy+, Dy− and Dz+, it is necessary to form a lower face of the movable electrode plate D in a three-dimensional manner, and this increases the manufacturing cost.